Crushing mill



Aug. 18, 1925. 1,550,013

A. c DAMAN CHUSHING MILL Original Filed June 20. 1922 2 Shuts-Sheet, 2

HFIFINBIBINk\ Patented ug 18, 1925.

UNITED STATES ARTHUR 0. Darren, or nnnvnn, COLORADO.

cnusmne MILL.

Application fiIedJune 20, 1922, Se ial No. 569,609. Renewed December 8,1924.

To all whom. it may concern:

Be it known'that I, -ARTH-UR C. DAMAN, a citizen of the United States, and a resident of 2813 Perry Street, Denver, in the county of Denver and State of Colorado,

have invented certain new and useful Improvements in Crushing Mills, of which the following is a clear, full, and exact descrip-. tion, such aswill enable others skilled in the art .to which it appertains to make and use the same.

This invention relates to mills adapted to the crushing of ore and like materials by the action of rolling and falling metallic balls and has for its principal object the provision of a mill of this character in which the fine granules will be rapidly removed thereby preventing the formation of a large amount of pulp which would interfere with the crushing action of the balls.

Anotherobject is to provide a mill of this character in which the liners and grates are made accessible for renewal by simply removing the head plate without the necessity of dismantling the machine or handling'the renewals through manholes as inthe present types of mills of this character.

A further object resides in the arrangement of a mill of this character in which two 0 independent crushing operations can be carried on simultaneously as with two independent mills, and yet there will be but a common point of feed, a single driving unit and only the normal number of bearin s and supports usually required in a sing e operation mill. This results ina great economy of parts, with theresultant low cost of manufacture, and also requires much less floor space than would be required for two independent machines.

Other objects and advantages reside in the detailed construction of the mill which lead to simplicity and efiiciency and which will become more apparent from the following description. Y

The invention will now be described in detail, reference being had to the accompanying drawing which forms a part .here

of; Like numerals refer to like parts throughout the following description and in all views of the drawin In the drawing: Fig. 1 is a side'elevation of the invention partly broken away. The lower half of this view is a longitudinal section taken on the line 11, Fig. 2.

Fig. 2 is a cross section taken on the line 2-2, Fig. 1.

Fig. 3 is an end elevation of the same looking in the direction of the arrow 3 Fig. 1. The lower half of this View is shown in section. segment being taken on the line 33, Fig. 1. The section in the lower right segment being taken on the line 3 --3 Fig. 1.

Fig. 4 is a plan view of a segment of grate bar. The perforations shown in this view are an alternate form from those shown in Fig; 3, otherwise the grate bars are similar.

Fig. 5 is a section through the grate bar, taken on the line 55, Fig. 3.

Fig. 6 is a' perspective view of one type of liner plate used within the invention, showing the lifter cast integrally therein.

Let the numeral 10 designate a mill bed or foundation, preferably of concrete, which supports a pair of bearings,.11, in which is carried a trunnion 12. Trunnion 12 is formed of two similar sections bolted together by means of flanges 13, formed thereon, at the mid point between'the bearings 11. Cast on the opposite extremities of the trunnion 12 are barrels supporting flanges 14.

The interior of trunnion 12 is lined by The section in the lower left means of two similar trunnion liners, 15,

each provided with a high worm or screw of proper pitch to carry material from the middle of the trunnion 12 toward the extremities thereof. One end of each trunnion liner 15 is closed. The closed ends'being butted' at the midpoint of the trunnion 12 forming a partition 16 therein.

Each section of the trunnion is provided with a spiral scoop, 17, turned in the proper direction to cause material to flow into the trunnion 12 as it is being revolved.

Mounted on each of the mill supporting flanges are ball containing barrels 18 and 19, adapted to contain metallic balls' 36. The construction of both the barrels 18 and 19 is similar with the exception that they are opposite hand, that is, barrel 18 wi discharge material to the left and barrel 19 to the right While being rotated in connection. The following description will therefore be limited to barrel 19 but will also apply to barrel 18.

Barrel 19 is secured to the trunnion 12 vby means of a circular, inner plate 20, bolted near its center to the barrel supporting flange 14 and carrying at its periphery a ring gear 21. A shell 22 surrounds the entire barrel and carries, at each edge, annular flanges 23 and 24. Flange 23 is securely bolted to the inner plate 20 while flange 24 carries a series of hinged stud bolts, 25, adapted to secure a head 26 on the end of the barrel. Head 26 is provided with a series of slots in its periphery to-receive the studs 25.

The head 26 is provided with an opening at its center, in which is fixed a discharge spout 27, and carries secured to its inner face a series of segmental shaped grate bars 28.

Grate bars are held in spaced relation to the head 26, by means of flanges 29 formed along the radial edges of each grate bar, thereby allowing a passageway between the grate bars 28 and the head 26. Flanges 29 are higher at their extremities near the apex of the segment and project outwardly into the discharge spout 27. Each grate bar and the flanges thereof is notched out for the passage of bolts 20 by means of which the grate bars 28 are secured to the head 26.

The grate bars 28 terminate before reaching the center of the mill, leaving an opening in which a flanged sleeve 31 is fixed. Sleeve 31 allows an opening into the interior of the mill 19 through which the operation may be observed.

It will be noted that upon loosening and throwing back the hinged studs, 25, the head 26 of the barrel can be readily removed, carrying with it the grate bars 28. This allows easy access to the interior of the barrel for renewals and repairs and facilitates the removal and renewal of the grate bars 28. This is one of the important features of the invention.

Upon theinner face of the inner plate 20 is secured a renewable liner 32, formed in a series of segments. A series of alternating renewable liner plates 33 and 36 is also secured to the inner face of the shell 22. Plates 36 are plain segmental plates.-

The construction of the liner plates 33 is believed to be new and novel and is one of the features of this invention. Extendin diagonally across each liner plate 33, an preferably cast integrally with the plate, is' a lifter 34. Lifter 34 is-transversely slotted, the distance between the slots increasing as the extremity toward the feed end of the barrel is approached.

A portion of the lifter 34 at the feed end extremity is left without slots. The liner plates 33 are so placed as to cause the lifters 34 to slant downward toward the feed end of the barrel 19 when they are onthe ascending side, as the mill is revolved, for the purpose of constantly working the coarse material back toward the feed end until it has been crushed fine enough to pass through the slots in the lifters 34 when it will pass out through the openings in the grate bars 28.

Ring gear 21 is in engagement with a driving pinion in the usual manner in mills of this character.

The operation of the mill is as follows: Material to be crushed is fed into a trough 35, which may if desired be formed in the foundation 10. .The mill is revolved in the direction of the arrow, Fig. 3, which causes the scoops 17 to alternately dig into the material and as they revolve carry it into the trunnion 12. The worms or screws on the trunnion liners 15 now carry the material into each of the barrels, 18 and 19, where it is crushed by the rolling and falling of the balls 36. previously placed in the barrel.

The fine granules, formed in the crushing, pass through the openings in the lifters 34 and work towards and pass through the openings in the grates 28. The flanges 29 of the plates 28 then act as lifters and raise these fines toward the top of the mill and allow them to fall by gravity down and out the discharge spout 27.

Water is fed into the barrels, with the materials to be crushed, through the trunnion 12, and discharges through the lower grates. This difference in elevation between the point where the feed enters the mill and where it discharges through the grate, causes a sluicing action which quickly carries the fines and slimes through the grates. After passing through the grates they are quickly removed by the lifting action of the flanges 29. The coarser particles are constantly being separated from the finer by the action of the slots in the lifters 34, and the coarse returned, by the angle of lifters 34, for regrinding.

This method of operation causes the fines to migrate faster through the mill than the coarse particles and relieves the mill of a bulky mass to pulp which would act to cushion the blows of the balls and also to reduce their relative weight by its buoyant action.

With the usual overflow type of ball mill, there is a vertical gravity classification of the mineral from the gangue. The mineral being heavier is carried to the periphery of the mill and in consequence is ground to an undersirable product. This is avoided in this invention by the rapid separation of the fines and their prompt removal. This rapid separation and removal of the fines is on of the principal features of the invention.

Should it be desired to use the mill as the usual over ow type, the grate bars 28 are removed and the mill operated in the usual manner. If desired, one of the barrels, 18 and 19, may be operated in the usual overflow manner and the other with the grates. The barrels, l8 and 19, may be also operated in tandem in closed circuit with a classifier, should a large ratio of crushing be desired. This increases the circulation through both mills and results in greater efliciency.

The grate bars 28 as shown in Figs. 1 and 3 have long slots of uniform width and uniform spacing, the series of slots ineach grate bar extend radially of the complete grate. Thisform of'grate is the preferred form in most installations. However, for certain classes of crushing the alternate form of grate, shown in Figs. 4 and 5, is desirable. This grate consists of a series of staggered perforations, the diameter of which slightly increases tolward the discharge to prevent clogging.

lVhile I have described andillustrated herein a specific form of my invention, 1

Wish it understood that the same may be. .1 I ARTHUR C. DAMAN.

varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is: v

1. In a crushing mill the combination with a rotary barrel, of a series of lifters on the interior surface. thereof said lifters being inclined at an angle to the axis of said barrel and provided with traverse slots for the purpose described.

2. A crushing mill comprising in combination a single hollow trunnion shaft connecting at each of its extremities with a ball containing barrel, said barrels being supported by hearings on said connecting shaft;

means for feeding material into said shaft near its mid-point and opposed screws on the interior of said shaft adapted to carry said material into both of said barrels.

In testimony whereof I afiix my signature. 

